Expected 1 arguments, but got 0. Did you forget to include 'void' in your type argument to 'Promise'?

[KBryan]

The following error Expected 1 arguments, but got 0. Did you forget to include 'void' in your type argument to 'Promise'? is found in buttons.ts.

Problem:
In newer versions of TypeScript 4.1.x the following syntax is not supported and will produce the above error.
function removeAllButtons() { return new Promise((resolve, reject) => { shownButtons.forEach(button => button.hide()); shownButtons = []; resolve(); }); }
Fix:
resolve is unknown in this context I assume and thus the following syntax works without error.
function removeAllButtons() { return new Promise<void>((resolve, reject) => { shownButtons.forEach(button => button.hide()); shownButtons = []; resolve(); }); }